A generator control system is coupled to a motor generator. The system includes a DC port, a first switch unit, a DC bus, a first power conversion circuit, a second power conversion circuit, and a second switch unit. The first power conversion circuit has a first side coupled to the DC bus and a second side coupled to the first switch unit. The second power conversion circuit has a first side coupled to the DC bus and a second side coupled to the motor generator. One end of the second switch unit is coupled to the first power conversion circuit and the first switch unit, and the other end of the second switch unit is coupled to the DC port.